Various display devices such as organic EL devices and liquid crystal display devices and electronic devices such as integrated circuit devices, solid imaging devices, color filters, and black matrices are provided with various resin films such as surface protective films for preventing deterioration or damage, flattening films for flattening the device surfaces, electrical insulating films for maintaining electrical insulation, and insulating films used in redistribution layers (RDL) formed on surface protective films.
In the past, as the resin materials for forming these resin films, thermosetting resin material such as epoxy resin and polyimide has been generally used. In recent years, along with the increasing density of interconnects and devices, for these resin materials as well, development of new resin materials excellent in electrical characteristics such as low dielectric constant, low temperature cureability, adhesion to metal, crack resistance, and moisture resistance has been sought.
To meet these demands, for example, Patent Document 1 discloses a radiation-sensitive resin composition containing a resin (A), a cross-linking agent (B) having an epoxy group, a cross-linking agent (C) having a triazine ring structure of glycoluril structure and having one or more functional groups selected from an imino group, methylol group, and alkoxybutyl group, and a radiation-sensitive compound (D). However, according to the radiation-sensitive resin composition described in this Patent Document 1, while it is possible to form a resin film excellent in electrical characteristics such as low dielectric constant, the film is not necessarily sufficient in adhesion to a metal layer of copper etc. There is therefore the problem that this could not be used for applications where such characteristics were demanded, for example, applications of insulating films for redistribution layers formed on surface protective films.